Tenant Not Signing Documents

General Discussion

My new tenant has been in the property since mid January. 

She signed and returned all the documents prior to moving in very quickly but she has not signed a third h since moving in, including an inventory and deposits document that I'm required to have by law.

I have told her I'll visit the property and gave her a time and day and she said she didn't know whether she would be around but would do her best.

If I travel to the property can I take my travel costs (26 miles away and at least a two hour round trip) out of her deposit?

What is the best way forward when there's documents to sign in the future?

Thanks for any advice.